Conventional greyscale display drivers have multiple bits of Display RAM per display segment according to number of greyscale. For example, 2 bits per segment for 4 greyscale levels, 3 bits per segment for 8 greyscale levels. On the other hand, to drive a monochrome (2-level) e-paper display, 4 different driving waveforms are utilized to drive each segment (black or white), which are: from white to white, from white to black, from black to white, and from black to black. The Display Data RAM has 2 bits per segment. Typical segment type e-paper display drivers do not support greyscale displays.
In addition, to drive an e-paper display panel, costly double layer flex connectors are typically required when the display panel and the driver IC pin assignment do not match. Retooling the display panel or the driver IC is another costly solution.